| Patent application number | Description | Published |
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| 20100089459 | MASS FLOW CONTROLLER AND METHOD OF OPERATING THE SAME - One embodiment of the present invention involves a thermal sensor and a method of using the same. One thermal sensor is adapted to output a signal which is unaffected by external longitudinal and orthogonal thermal gradients. In one embodiment, the mass flow controller thermal sensor comprises a capillary tube having an upstream tube portion, a tube bend portion, and a downstream tube portion, the downstream portion being substantially parallel to the upstream portion. A distance between the upstream tube portion and the downstream tube portion in one embodiment is no greater than half the upstream portion and downstream portion lengths, a first pair of thermal sensing elements are coupled to the upstream tube portion and a second pair of thermal sensing elements are coupled to the downstream tube portion. | 04-15-2010 |
| 20100180951 | Mass Flow Controller Hysteresis Compensation System & Method - A method of characterizing hysteresis as a function of a device output comprising, applying an input signal across a first input signal range to a device, the input signal inducing a device function having a first output with a first output value range dependent upon the first input signal range. The input signal is further applied across a second input signal range to the device, the input signal inducing the device function to have a second output with a second output value range dependent upon (i) the second input signal range and (ii) device hysteresis. A difference between the second input signal range and the first input signal range is then measured across the first and second output value ranges. A method of operating a mass flow controller valve and a mass flow controller are also contemplated. | 07-22-2010 |
| 20110015791 | THERMAL MASS FLOW SENSOR WITH IMPROVED RESPONSE ACROSS FLUID TYPES - One embodiment of the present invention comprises a mass flow controller. The mass flow controller may comprise a pair of thermal sensing elements, a bridge circuit adapted to receive at least one first signal from the pair of thermal sensing elements and a differential amplifier adapted to (i) receive at least one bridge signal from the bridge circuit, and (ii) emit an output signal generally proportional to a flow rate of fluid passing through the mass flow controller. The mass flow controller is also comprised in one embodiment of a filter portion of a control module having one or more first filters comprising substantially permanent parameters adapted to provide a more accurate output signal for a baseline fluid upon a change in the flow rate and one or more second filters comprising variable parameters, with each of the one or more second filters being adapted to provide a more accurate output signal for non-baseline fluids upon a change in the flow rate. | 01-20-2011 |
| 20110054702 | MULTI-MODE CONTROL LOOP WITH IMPROVED PERFORMANCE FOR MASS FLOW CONTROLLER - One embodiment of the invention comprises a mass flow controller comprising a digital controller, a valve, and a sensor. The digital controller is adapted to implement a control loop having a proportional signal modifier in series with an integral signal modifier. The integral signal modifier is adapted to receive a combination signal and output an integrated signal. The valve is adapted to receive the integrated signal and adjust a valve opening in accordance with the integrated signal. The sensor is adapted to output a measured flow rate signal indicative of an actual fluid flow rate in the mass flow controller. The measured flow rate signal is received by the proportional signal modifier and used in conjunction with a setpoint signal to determine the error signal. | 03-03-2011 |
| 20110061841 | TEMPERATURE INSENSTIVE MASS FLOW CONTROLLER - A temperature insensitive mass flow controller comprising a main flow line, a capillary tube coupled to the main flow line across a bypass a thermal sensing element coupled to the capillary tube and a mass flow controller housing adapted to at least cover the capillary tube. A first heat sink has been coupled to the mass flow controller internal to the mass flow controller housing and coupled to the capillary tube. The heat sink being adapted to control a temperature of a gas in the capillary tube. | 03-17-2011 |
| 20110247390 | METHOD AND MASS FLOW CONTROLLER FOR ENHANCED OPERATING RANGE - A mass flow controller (MFC), a method for calibrating an MFC, and a method for operating an MFC are disclosed. The method for calibrating the MFC includes obtaining data relative to two signals from a thermal mass flow sensor when operating the mass flow controller at different flow rates with a calibration gas, and storing the data relating to the two signals in connection with corresponding flow-rate values. The method for operating the MFC includes obtaining data relative to the two signals from the thermal mass flow controller and accessing the calibration data to determine an unknown flow rate for a process gas that may be the same gas as the calibration gas or may be another gas that is different from the calibration gas. | 10-13-2011 |
| 20110247696 | MASS FLOW CONTROLLER WITH ENHANCED OPERATING RANGE - A mass flow controller among other embodiments and method is described. The mass flow controller including a thermal mass flow sensor including at least two sensing elements coupled to a sensor tube of the mass flow controller, the thermal mass flow sensor being designed to provide a first signal indicative of flow of a gas within a first flow-rate-range and a second signal indicative of flow of the gas within a second flow-rate-range; and a control portion figured to control a valve position of the mass flow controller responsive to the first signal when the flow of the gas is within the first flow-rate-range and control the valve position of the mass flow controller responsive to the second signal when the flow of the gas is within a second flow-rate-range. | 10-13-2011 |
| 20110264281 | METHOD AND SYSTEM OF ON-TOOL AND ON-SITE MFC OPTIMIZATION PROVIDING CONSISTENT RESPONSE - One method of obtaining an initial adjusted mass flow controller valve start position comprises obtaining a mass flow controller delay period and setting a mass flow controller valve to an initial valve opening position that is less than an expected optimal valve opening position. An initial desired flow rate and initial operating conditions are input into a control system that is in communication with the valve, and the control system is initiated. The control system is adapted to adjust the valve opening position to achieve the initial desired flow rate, while taking into account flow rate and valve position feedback to the control system. During operation of the MFC and control system, the valve position and the flow rate are recorded in one embodiment and a flow rate that one of meets and exceeds a threshold is detected. An initial-flow time-period extending from the time of control system initiation to detection of the threshold being one of met and exceeded is determined and the mass flow controller delay period from the initial flow time period is subtracted from the initial-flow time-period to obtain an adjusted start time. The valve opening position at the adjusted start time is set as the initial adjusted mass flow controller valve start position. | 10-27-2011 |
